CUCKOO. 603 



or erroneous ; and the attempts of the moderns towards its inves- 

 tigation have been confined within very narrow limits; for they 

 have gone but little farther in their researches than to examine the 

 constitution and the structure of the bird, and having found it pos- 

 sessed a capacious stomach with a thin external covering, conclud- 

 ed that the pressure on this part, in a sitting posture, prevented 

 incubation. They have not considered that many of the birds 

 which incubate, have stomachs analogous to those of cuckoos : the 

 stomach of the owl, for example, is proportionably capacious, and 

 is almost as thinly covered with external integuments. Nor have 

 they considered that the stomachs of nestlings are always much 

 distended with food ; and that this very part, during the whole 

 time of their confinement to the nest, supports, in a great degree, 

 the weight of the whole body ; whereas, in a sitting bird, it is not 

 nearly so much pressed on ; for the breast in that case fills up 

 chiefly the cavity of the nest, for which purpose, from its natural 

 convexity, it is admirably well fitted. 



These observations, I presume, may be sufficient to shew that 

 the cuckoo is not rendered incapable of sitting, through a peculia- 

 rity either in the situation or formation of the stomach ; yet, as 

 a proof still more decisive, I shall state the following fact. la 

 the summer of the year 1786, I saw, in the nest of the hedge- 

 sparrow, a cuckoo, which, from its size and plumage, appeared 

 to be nearly a fortnight old. On lifting it up in the nest, I ob- 

 served two hedge-sparrow's eggs under it. At first I supposed 

 them part of the number which had been sat on by the hedge- 

 sparrow with the cuckoo's egg, and that they had become addle, 

 as birds frequently, suffer such eggs to remain in their nests with 

 their young; but on breaking one of them I found it contained a 

 living fectus ; so that of course these eggs must have been laid se- 

 veral days after the cuckoo was hatched, as the latter now com- 

 pletely filled up the nest, and was by this peculiar incident per- 

 forming the part of a sitting-bird*. 



Having under my inspection, in another hedge-sparrow's nest, 

 a cuckoo, about the same size as the former, I procured two 

 wagtail's eggs which had been sat on a few days, and had them 



* At this time 1 was unacquainted with the fact, <hat the young cuckoo 

 turned out the eggs of the hedge-sparrow ; but it is reasonable to conclude, 

 that it had lost the disposition for doing this when these eggs were deposited in 

 the nest. Orig. 



